1. Field of the Invention
The present invention relates to a wireless communication device.
2. Description of the Related Art
In recent years, with the remarkable spread of data communication that is performed in a wireless manner, there have been advances in high communication speed, miniaturization of a wireless communication device, low power consumption, and improvement in security technology.
A technology for low power consumption by the wireless communication device that is used in a sensor or the like is disclosed in Japanese Patent Unexamined Publication Nos. 2013-98884 and 2013-236393. Wireless communication devices that are disclosed in Japanese Patent Unexamined Publication Nos. 2013-98884 and 2013-236393 reduce power consumption in a waiting state until a sensor performs detection, by powering off main components for wireless communication, such as a wireless unit, a control unit, and the like. Furthermore, the wireless communication devices store a failure situation at the time of communication in a state storage unit to which power is always supplied, and switch a base-unit detection operation for the wireless communication when the sensor becomes responsive, in a normal state or in a state where a communication failure takes place. Thus, a reduction in power consumption is realized.
Wireless communication in compliance with a Digital Enhanced Cordless Telecommunications (DECT) scheme that has been spread worldwide as a communication scheme for digital cordless telephones is stipulated in ETSI EN 300 175-2: “Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 2: Physical Layer (PHL),”ETSI EN 300 175-3: “Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 3: Medium Access Control (MAC) layer,” and ETSI EN 300 175-5: “Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 5: Network (NWK) layer.” Also in Japan, the use of wireless devices in compliance with the DECT scheme was approved, and wireless communication devices such as a cordless telephone and an intercommunication system have been of practical use. In recent years, a system in which household electrical appliances within a house are controlled from outside of the house, a household crime prevention system, or the like has gained popularity. Developments in wireless communication for communication between apparatuses on such a home automation network have been made. A method for packet communication suitable for communication between apparatuses on the home automation network, which is based on the wireless communication in compliance with the DECT scheme, is stipulated in “ETSI TS 102 939-1: “Digital Enhanced Cordless Telecommunications (DECT); Ultra Low Energy (ULE); Machine-to-Machine Communications; Part 1; Home Automation Network (Phase 1)” (communication stipulated in ETSI TS 102 939-1: “Digital Enhanced Cordless Telecommunications (DECT); Ultra Low Energy (ULE); Machine-to-Machine Communications; Part 1; Home Automation Network (Phase 1)” is hereinafter referred to as DECT ULE communication).
In such packet communication, data is stored in a packet to which a number is added, transmission of and reception of data are performed on a packet-by-packet basis, re-transmission control is performed using the number that is added to the packet, and the transmission of and the reception of data are performed. In a case of the DECT ULE communication, when the data to be transmitted or received is not present, the wireless communication is interrupted, and when the transmission of the data starts, the packet communication is resumed with a simple sequence. Furthermore, regardless of the interruption of the wireless communication, the packet communication is performed using consecutive packet numbers. Thus, low power consumption and a reduction in data transmission delay are realized. In such packet communication, encryption or authentication of communication data for improving security is performed. In a case of the DECT ULE communication, with encryption communication that uses a counter with cipher block chaining message authentication code (CBC-MAC), security improvement in the packet communication is realized.